Flexible shaft coupling



' July 10, 192a 1,676,242 G. M. BARTLETT FLEXIBLE SHAFT COUPLING FiledAug 25, 1925 g 25 in each of the fi Patented July 10, 1928.

' UNITED STATE-' GEORGE M. BARTLETT, OF INDIANAPOLIS, INDIANA.

FLEXIBLE snns'r COUPLING.

Application filed August 25, 1925. Serial No. 52,439.

This invention relates to couplings for connecting two shaft ends insuch a way as to allow power to be transmitted between the 7 two endswhen the respective axes of the 5 two shafts are not precisely in thesame straight line.

The object of'my invention is to provide a flexible-coupling that willproduce the least 'po'ss'ble side stresses on the hearings in which theconnecting shafts turn.

Another object is to make provision for longitudinal motion of eithershaft.

A further. object is to provide a coupling in which the driving forcewill be egually divided between points on opposite si' es of the shaftaxes. v I In the accompanying drawings, Figure 1 is an end view of acoupling and illustrating in simple form the link-work which representsthe basic principle on which my coupling is constructed. Fiighr'e 2 isan end view of a practical .modi cation of Figure 1. Figure 3 is a' sideview of Figure 2.

The same numerals apply to similar parts gures.

Referring to Fig. 1 the driving shaft 2 is perpendicular to the plane ofthe drawing. The transverse piece 3 is secured to the shaft end and hasnotches at its ends to receive certain chain parts; in this case therollers of a roller chain. The transverse piece 6 is similar to 3 butarran ed at right angles to it, and is secured to t e end of the driven,shaft 7 not shown in this figure. The floats s5 ing cross bars 1 and 8are located between the members 3 and 6 but v with them nor with oneanother. They are notched at their ends like members 3' and 6. A chain4--5-910 engages the notches of the transverse members 3 and 6 and ofthe cross bars 1 and 8.

If the axes of the two shafts 7 and 2 lie in the same straight line andshaft 2 is rotated in the direction shown, the chain sec- 65 tions'109will be in tension and will drive the transverse piece 6 from bothends'caus ing the shaft 7 to rotate. The cross bars 1 and 8 will notalter their relative positions,

If the drivin shaft turns in the opposite to direction the c ainsections 4-5 .will then be in tension.

' If however the axes of the two shafts should not be coincident, thecross bars 1 and 8 then act as compensators keeping the chain frombecomin either too tight or too loose by. means of t eir free floatingaction.

"nectin terme iate members; respectively; the two not sensibly incontact member,

Relative motions will be set up between the parts 1, 4, 5, 8, 9 and 10which allows the driving forces to be equally divided between the twoends of member 3 and also the two ends of member 6. Thisrelievesthe'shaft bearings of practically all side stresses and insures thetransmission of rotary motion to the driven shaft at a uniform angularvelocity ratio. v

A longitudinal shaft motion is provided for by making the thickness ofmembers 3 and 6 somewhat less than the width of the chain. Thisprovision also permits an an- 7 gular misalignment between the shafts.

Figure 2 shows an end view, and Figure 3 a side view of one form of thiscoupling designed for use with a roller chain.

I claim as my invention 2' 1. In a flexible shaft coupling, the combi- 1nation of. two shaft ends in general alinement, two intermediatemembers, two pairs of chain sections connecting one shaft end to the twointermediate members respectively, and two pairs of chain sectionsconthe other shaft end to thetwo in= chain sections of ca h pair beingono 0- site sides of the genetal axis of the coup m and extendingcircumferentially in the same direction from the intermediate member,the chain sections of one pair associated with each shaft end extendingin the-opposite cir- 1 cumferential direction from the chain sections ofthe other pair connected with that shaft end, so that one pair of thechain sections for each shaft end is always in tension regardless of'thedirection of torque between v the two shaft ends and the line joiningthe middle points of the chain sections of one pair connected toanintermediate member being circumferentially displaced from the linejoining" the middle pointsof the links of the other pair connected tothat intermediate no two consecutive chain sections being in alinement,and the ends of the chain sections being flexibly connected with theshaft ends in such a manner as to permit motion in the direction of theshaft axis.

2. In a flexible shaft coupling, the combi- 1 nation of two shaft ends1n general alinement, two intermediate members, two pairs of chainsconnecting one shaft end to the two intermediate members respectively,and two, pairs of chains connecting the other shaftendto the twointermediate members respectively; the two chains of each pair be- 7 ingon opposite sides of the general axis of the coupling, the links of onepair associated with each shaft end extendin in the oppositecircumferential direction %rom the links of the other pair connectedwith that shaft end, so that one pair of the chains for each shaft endis always in tension regardless of the direction of torque between thetwoshaft ends; and the line joining the middle points of the chains ofone pair connected to an intermediate member belng circumferentiallydisplaced from the line joining. the

two consecutive chains being in alinement,

and the chains being flexibly connected with the shaft ends in such amanner as to permit motion parallel to the shaft axis.

In witness whereof, I have hereunto set my hand at Indianapolis,Indiana,'this 7th day of August, A. D. one. thousand nine hundred andtwenty-five,

GEQRGE M. BARTLETT.

